Life Sciences Commons^™

Interaction Between The Component Enzymes Of The Glycine Decarboxylase Multienzyme Complex, David J. Oliver, Michel Neuburger, Jacques Bourguignon, Roland Douce

David J. Oliver

The glycine decarboxylase multienzyme complex comprises about one-third of the soluble protein of the matrix of pea (Pisum sativum) leaf mitochondria where it exists at a concentration of approximately 130 milligrams protein/milliliter. Under these conditions the complex is stable with an approximate subunit ratio of 2 P-protein dimers:27 H-protein monomers:9 T-protein monomers:1 L-protein dimer. When the complex is diluted it tends to dissociate into its component enzymes. This prevents the purification of the intact complex by gel filtration or ultracentrifugation. In the dissociated state the H-protein acts as a mobile cosubstrate that commutes between the other three enzymes and shows …

Tests Of Three Hypotheses Of Hatching Asynchrony In The Common Tern, Patricia B. Bollinger, Eric K. Bollinger, Richard A. Malecki

Eric K. Bollinger

We examined three hypotheses concerning hatching asynchrony in the Common Tern (Sterna hirundo). Survival of third-hatching "C-chicks" was significantly lower than that of "A-" and "B-chicks" in broods of three. In 2 yr when conditions did not appear favorable, survival was significantly higher in manipulated broods in which chicks hatched synchronously (73%) than in nonmanipulated broods (56%). Chicks in synchronous broods grew significantly faster than C-chicks and at a rate similar to A- and B-chicks. These results were inconsistent with the brood-reduction hypothesis, which predicts that hatching asynchrony will maximize brood success under conditions of food limitation. Chicks hatching from …

Verbenone Bubble Caps Ineffective As A Preventive Strategy Against Mountain Pine Beetle Attacks In Ponderosa Pine, C. K. Lister, J. M. Schmid, S. A. Mata, D. Haneman, C. O'Neil, J. E. Pasek, L. Sower

Judith E Pasek

Verbenone capsules were stapled to trees in mountain pine beetle-infested stands of ponderosa pine at densities of 10, 20, 40, and 68 capsules per acre. Mean numbers of infested trees were not significantly different among treatments. Either the verbenone is not effective in repelling attacks or the formulation in the capsules needs to be modified to enhance its effectiveness. Verbenone capsules were not effective enough to be used in a preventive strategy.

Antiepileptic Drugs: Pharmacological Mechanisms And Clinical Efficacy With Consideration Of Promising Developmental Stage Compounds, Michael A. Rogawski, Roger J. Porter

Michael A. Rogawski

No abstract provided.

Preparing For Africanized Honey Bees: Evaluating Control In Mating Apiaries, Richard L. Hellmich Ii, Gordon D. Waller

Richard L Hellmich

A measure of queen mating control at an apiary is the number of matings with managed drones expressed as a percentage of total matings (managed and feral drones). In Texas, USA, using cordovan queens and drones for tests in July, it was found that at a commercial apiary near other apiaries 93% of all matings were with managed drones. At an isolated (outlying) apiary, the figure was 83%. It is estimated that in April-May, when most queens are produced in this area, mating control would be 96-98% and 93-96% respectively. It is concluded that 90-95% is a realistic level for …

Surface Moisture And Osmotic Stress As Factors That Affect The Sanitizing Of Beef Tissue Surfaces, James S. Dickson

James S. Dickson

The use of osmotic stress or desiccation in combination with 2% acetic acid reduced the numbers of Salmonella typhimurium or Listeria monocytogenes on beef tissue to a greater degree than the acid alone. Bacteria were osmotically stressed by NaCl, CaCl2, or sucrose solutions. Pre-washing with 20% NaCl followed by sanitizing with acetic acid reduced the numbers of S. typhimurium an additional 1.5-to 2-log cycles compared with acetic acid alone. Similar reductions were seen by allowing the tissue surfaces to dry before the application of the acid. Desiccation in combination with acetic acid was also effective in reducing the numbers of …

Red-Bellied Woodpecker Predation On Nestling House Wrens, Given Harper, Andrew J. Neill

Given Harper

No abstract provided.

Https://Www.Supplementmegamart.Com/Cerisea-Medica-Plus/, Ceera Zngi

ceera zngi

Use Of A Bacteriocin Produced By Pediococcus Acidilactici To Inhibit Listeria Monocytogenes Associated With Fresh Meat, J. W. Nielsen, James S. Dickson, J. D. Crouse

James S. Dickson

A bacteriocin produced by Pediococcus acidilactici had an inhibitory and bactericidal effect on Listeria monocytogenes associated with fresh meat. MICs were significantly lower than minimum killing concentrations. When meat was inoculated with L. monocytogenes, the bacteriocin reduced the number of attached bacteria in 2 min by 0.5 to 2.2 log cycles depending upon bacteriocin concentration. Meat treated initially with the bacteriocin resulted in attachment of 1.0 to 2.5 log cycles fewer bacteria than that attained with the control. The bacteriocin, after 28 days of refrigerated storage on meat surfaces, was stable and exhibited an inhibitory effect on L. monocytogenes.

Minyak Bulus Asli Kalimantan Untuk Pria Atau Untuk Wanita, Ripan Maki

ripan maki

Http://Www.Worldcarestore.Com/Abc-Forskolin/, Printol Thor

printol thor

Nucleotide Sequence And Further Characterization Of The Synechococcus Sp. Strain Pcc 7002 Reca Gene: Complementation Of A Cyanobacterial Reca Mutation By The Escherichia Coli Reca Gene, R C. Murphy, G E. Gasparich, D A. Bryant, R D. Porter

Gail Gasparich

Achene Microstructure In Eriophorum L. (Cyperaceae): Systematic Implications And Paleobotanical Applications, Gordon C. Tucker, Norton G. Miller

Gordon C. Tucker

Silica bodies in the outer cells of the achene epidermis in 17 species of Eriophorum-and nine species of Scirpus, some of which have been placed in Eriophorum, were revealed by sonication and/or acetolysis and examined by scanning electron microscopy. A silica body consists of a basal platform, one or more large elevated protuberances, and sometimes smaller satellite protuberances. Individual species differ in the number of protuberances, the presence/absence of satellites, the texture of the platform, and the occurrence of nodules on the larger protuberances. These features, combined with achene shape and characteristics of the anticlinal walls of the epidermal cells …

The Genera Of Arundinoideae (Gramineae) In The Southeastern United States, Gordon C. Tucker

Gordon C. Tucker

No abstract provided.

Genotypic And Chemical Influences On Fruit Growth Of Tomato, Henry R. Owen, Louis H. Aung

Henry R. Owen

A relationship between ovary size at anthesis and final fruit diameter of 12 tomato (Lycopersicon esculentum Mill.) cultivars with a range of fruit sizes, shapes, and maturation rates was determined. ‘Fireball’, ‘Michigan/Ohio Hybrid’, and ‘New Yorker’ produced nonfasciated, spherical fruits of intermediate maturation rate and showed a significantly higher correlation between ovary diameter at anthesis and final fruit diameter than ‘Small Fry’, ‘Roma VF’, ‘Early Cascade’, ‘Campbell 1327’, or ‘Ponderosa’. A linear regression of final fruit diameter at maturity on ovary diameter at anthesis of the cultivars was highly significant (r2 = 0.92**; ÿ = 22.5X - 0.3). Continuous root …

Food Quality, Heterozygosity, And Fitness Correlates In Peromyscus Polionotus, James M. Novak, William R. Teska, Michael H.. Smith

James M. Novak

Oldfield mice (Peromyscus polionotus) that are more heterozygous utilize food and maintain body weight under varying degrees of dietary stress better than their less heterozygous counterparts. Mice were collected in southern Florida and fed diets of three qualities. During each dietary treatment, body weight, amount of food eaten, amount of food absorbed, and feeding efficiency were determined. Body weights for all mice decreased during the experiment. More heterozygous mice maintained their weight better during periods of dietary stress than those that were less heterozygous. Mice with different levels of genetic variability had essentially the same mean feeding efficiency with high …

Morphological Asymmetry And Interspecific Hybridization: A Case Study Using Hylid Frogs, Trip Lamb, James M. Novak, Diane L. Mahoney

James M. Novak

The limited studies addressing developmental stability of interspecific hybrids suggest a positive association between the level of fluctuating asymmetry and 1) the degree of divergence between parental species, and 2) the recency of the contact zone. To evaluate these associations, we examined asymmetry in a recentlyestablished hybrid population of treefrogs (Hyla cinerea and H. gratiosa) that show marked structural gene divergence. Fluctuating asymmetry (FA), directional asymmetry, and antisymmetry were assessed for eight paired osteometric traits in allozymically-defined parental and hybrid categories. FA levels varied considerably among traits. Nonetheless, for any given trait, the hybrid categories did not demonstrate elevated levels …

Trophic Interactions Between Fish And Invertebrates In Bear Lake, Utah-Idaho, Wayne A. Wurtsbaugh

Wayne A. Wurtsbaugh

An intensive study of the limnology, invertebrates and fishes of Bear Lake was conducted in 1987 in order to define the productivity and food web of the community. Limno10gica1 parameters and invertebrates were measured at approximately monthly intervals while fish distribution and feeding was analyzed in February, June, August, and October. Samples were collected at three to eight stations along a transect running from the shallow littoral area on the west side of the lake, to the deep profundal zone.

The Effect Of Selenium On Sulfur Uptake By Barley And Rice, Robert Mikkelsen, Hongfu Wan

Robert Mikkelsen

Because of their chemical and physical similarities, plant uptake of sulfur and selenium are closely related. Barley and rice were grown in greenhouse solution culture to examine the synergistic interactions between sulfate and selenate in plant uptake. In the presence of low concentrations of solution sulfate, shoot and root yields were decreased with additions of selenate. However, when sulfate was present in elevated concentrations, no selenium-induced yield reductions occurred. A synergistic interaction between sulfate and selenate caused an increase in the shoot sulfur concentrations with increasing concentrations of selenate at low sulfate solution concentrations. At elevated sulfate concentrations, no synergism …

Biuret In Urea Fertilizer, Robert Mikkelsen

Robert Mikkelsen

Urea has become the leading form of N fertilizer worldwide. Historically there has been concern about biuret formed during the manufacturing of urea fertilizer and the potential adverse effect of biuret on plant growth. In this paper, the fate of biuret in soils and its phytotoxicity is reviewed. Biuret is mineralized by many soil micoorganisms, but the process is much slower than for urea. Excessively high biuret concentrations can damage seedlings and, like urea, should not be placed in close proximity to germinating seeds. Crop tolerance to biuret varies according to the plant species, soil conditions, fertilizer placement, and method …

Stratification Not Required For Tree-Of-Heaven Seed Germination, William R. Graves

William R Graves

Tree-of-heaven (Ailanthus altissima (Mill.) Swingle) seed germination and shoot dry weight were determined after stratifying samaras at 5 and 25 °C for up to 28 days. Seeds of samaras stratified at 5 °C for 0, 4, and 12 days showed 70, 77, and 96% germination, respectively, 7 days after sowing. Fourteen days after sowing, 90% of nonstratified seeds had germinated, but shoot weight of nonstratified seedlings was 16% less than that of seedlings from fruit stratified at 5 °C for 12 days. Germination 7 days after sowing was greater after stratification at 5 °C than at 25 °C, but the …

Flight Characteristics Of Foraging Africanized And European Honey Bees (Hymenoptera: Apidae), Robert G. Danka, Richard L. Hellmich Ii, Anita M. Collins, Thomas E. Rinderer, Vernon L. Wright

Richard L Hellmich

Interfloral movement and visitation parameters were quantified for individual Africanized and European honey bees (Apis mellifera) foraging in a field of sesame in Venezuela. The 2 bee types showed nearly identical movement and visitation characteristics for most of the parameters measured. Africanized bees spent slightly less time per flower visit (mean ± SD; 10±4 s vs. 12±6 s) and tended to travel at a slightly faster rate (210±150 cm/min vs. 180±120 cm/min.) The frequencies of visits for various resources differed; Africanized bees collected only pollen on 51% of visits and only nectar on 22% of visits, whereas for European bees, …

Introduction: Structural Properties For Determining Mechanisms Of Toxic Action, Steven P. Bradbury, Robert L. Lipnick

Steven P. Bradbury

The U.S. Environmental Protection Agency (EPA), under a variety of Federal legislation, is charged with the responsibility of assessing the hazards of chemicals to human health and the environment. In some cases EPA incorporates predictive techniques in its decisionmaking processes. In the context of some statutes, predictive toxicological methods can be cost-effective components in an overall approach for prioritizing chemicals for in-depth toxicological investigation. Predictive approaches are also used where empirical toxicological data are either unavailable or not required under a specific statute. For example, under Section 5 of the Toxic Substances Control Act (TSCA), EPA's Office of Toxic Substances …

Influence Of Cytochrome P450 Mixed-Function Oxidase Induction On The Acute Toxicity To Rainbow Trout (Salmo Gairdneri) Of Primary Aromatic Amines, Steven P. Bradbury, Joop L. M. Hermens, Steven J. Broderius

Steven P. Bradbury

The influence of enzyme induction on the acute toxicity of aniline and 4-chloroaniline to rainbow trout (Salmo gairdneri) was investigated. For these two xenobiotics, bioactivation reactions are known to occur in mammals. Induction of cytochrome P450 mixed-function oxidase was obtained by intraperitoneal (ip) injection of trout with a mixture of polychlorinated biphenyls (Aroclor 1254). Five days after ip injection with three different doses of Aroclor 1254 (50. 100. and 200 mg/kg). benzo[a)pyrene hydroxylase activity in trout liver microsomes increased five- to sixfold. Cytochrome P450 concentrations in the microsomes were slightly. but significantly. enhanced in two of the three dose levels. …

Evaluation Of Chicken Heterophil Adherence, Claire B. Andreasen, Kenneth S. Latimer, W. L. Steffens

Claire B. Andreasen

Adherence of chicken heterophils was evaluated at 37 C using preconstructed columns containing various weights of nylon fiber (75 mg, 100 mg, or 125 mg) and whole blood anticoagulated with sodium heparin or 10% disodium ethylenediamine tetraacetic acid (EDTA). Additionally, 50-mg and 75-mg nylon fiber columns incubated at 41 C were used to evaluate heterophil adherence at an increased temperature. The mean percent adherence for heparin-anticoagulated blood applied to 75-mg, 100-mg, and 125-mg nylon fiber columns at 37 C was 76%, 92% and 97.4%, respectively. Samples applied to 50-mg and 75-mg columns at 41 C had adherence values of 27% …

Forage Quality Of Genetically Diverse Alfalfa Germplasms At Four Phenological Growth Stages, Andrew W. Lenssen, E. L. Sorensen, G. L. Posler

Andrew W. Lenssen

Forage quality of various alfalfa (Medicago sativa L.) cultivars has been determined under different environmental conditions, and numerous trials with alfalfa have documented an inverse relationship between forage quality and maturity. Little information is available, however, regarding the comparative forage quality of the germplasm sources from which most USA cultivars were developed. We compared forage quality of these germplasm sources at four phenological stages under disease- and insect-free conditions in a greenhouse. Germplasm sources (cultivars) tested were: Indian (Sirsa # 9), African (African), Peruvian (Hairy Peruvian), Flemish (DuPuits), Turkistan (Lahontan), Chilean (Kansas Common), M. varia (Grimm), and Ladak (Ladak). Four …

Organ Hypertrophy And Responses Of Colon Microbial Populations Of Growing Swine To High Dietary Protein, James S. Dickson, Wilson G. Pond, Vincent H. Varel, Friday O. I. Anugwa, Gary S. Ross

James S. Dickson

Thirty-two castrated male crossbred growing pigs (average initial wt 26.9 kg) were used to determine the effect of a high level of dietary protein (37%) compared with a normal level of protein (15%) on enterobacteria and Campylobactersp. inhabitation in the large intestine and on visceral organ hypertrophy and the interrelationships between these two factors. Pigs were kept in pairs (eight pens of two pigs/diet) and fed their respective diets ad libitum. Eight pigs (two pens of two pigs fed each diet) were killed at wk 4, 8. 12 and 16 without fasting. Fecal samples were obtained every 2 wk from …

Transfer Of Listeria Monocytogenes And Salmonella Typhimurium Between Beef Tissue Surfaces, James S. Dickson

James S. Dickson

Beef tissue surfaces were inoculated with either Listeria monocytogenes or Salmonella typhimurium and placed in contact with uninoculated tissue surfaces. The transfer of bacteria from one surface to another was determined under conditions designed to simulate contamination during meat processing. Bacterial transfer decreased when the initial inoculum was allowed to adsorb to the base tissue prior to contact with the second tissue. The type of base tissue was a factor (P<0.05), with a greater transfer from fat with contact times of less than 1 min and a greater transfer from lean with longer contact times.

Comparison Of Homogenization By Blending Or Stomaching On The Recovery Of Listeria Monocytogenes From Beef Tissues, James S. Dickson

James S. Dickson

Homogenization by blending or stomaching was compared for the recovery of Listeria monocytogenes from inoculated intact beef tissue. There were no differences in numbers of recovered bacteria (P > 0.10) attributable to either homogenization time or method. Fewer viable bacteria (PcO.05) were recovered in phosphate buffer than either buffered peptone water or 2% trisodium citrate buffer. Tween 80 increased the numbers of bacteria recovered from fat tissue (PcO.05). Stomaching is an acceptable method for homogenizing samples for Listeria analysis.

Multi-Isfet Sensors For Soil Nitrate Analysis, Stuart J. Birrell, John W. Hummel

Stuart J. Birrell

The management of a field as a heterogeneous area is now being investigated by many researchers in universities, companies, and research institutions. However, for site-specific application of inputs, it is necessary to develop systems to sense the variation of important properties in real time. Several studies have shown that ion selective electrodes can be used to measure soil nitrates. This work involves an investigation in the use of Ion Selective Field Effect Transistors (ISFETs), to measure soil nitrate levels.